Who should ‘use’ this?
The question was about an SBC being able to boot generic aarch64 OS images. So if you (as Radxa) want to make this happen, then ship Rock 5C with this SPI flash module in the eMMC slot and preflash something to it that would allow users to insert an USB stick containing an installation media of any generic aarch64 OS image.
Won’t happen anytime soon or at all. Linux on ARM is pretty much PITA.